Water-insoluble dyestuffs



2,865,910 WATER-INSOLUBLE DYESTUFFS Christian Zickendraht, Binningen,Switzerland, assignor 5 t Ciba Limited, Basel, Switzerland, 21 Swissfirm No Drawing. Application December 6, 1955 Serial No. 551,211'

Claims priority, application Switzerland December 16, 1954 7 Claims.(Cl. 260-147) This invention provides valuable new water-insolubledyestuffs which are isothiuronium salts of which the anion is that of achromiferous monoazo-dyestuff.

The invention also provides a process for the manufacture of theaforesaid water-insoluble dyestuffs, wherein an acid .chromiferousmonoazo-dyestuff is reacted with a derivative of isothiourea.

As acid chromiferous monoazo-dyestulfs there may be mentioned, moreespecially, those which contain a sulfone group, a sulfonic acid amidegroup, a carboxylic acid group or preferably a sulfonic acid group.

Among these dyestuffs there may be mentioned, for example, the so-called1:2-monoazo-dyestutf--chromium complexes which contain one atom ofchromium bound in complex union to two molecules of monoazo-dyestuif,and above all the so-called 1:1-chromium complexes of monoazo-dyestuffscontaining sulfonic acid groups, which complexes contain one atom ofchromium in complex union per molecule of monoazo-dyestuff, such as thedyestuffs known in commerce under the name Neolan dyestuffs.

A large number of chromiferous dyestuffs suitable for the presentprocess are known, but those which are not known can be made by methodsin themselves known.

As derivatives of isothiourea to be used as starting materials in thepresent invention there are to be understood those water-solubleS-isothiourea derivatives which contain an isothiuronium cation, such asisothiuronium bases (provided they are stable) and above allisothiuronium salts of organic or preferably inorganic acid, forexample, isothiuronium halides and if desired mixtures thereof. Therecome into consideration, for example, S-acyl-isothiuronium halides, butmore especially isothiuronium salts which contain bound to the sulfuratom of the isothiuronium ion an aliphatic, alicyclic or heterocyclicradical, such as S-cycloalkyl-isothiuronium 5O chlorides andS-alkyl-isothiuronium chlorides, or a radical, advantageously anaromatic radical, bound through an alkylene or alkylidene group. Thesubstituent bound to the sulfur atom is advantageously one that is freefrom groups imparting solubility in water. it may, how- 59 ever, containother substituents, such as acyl groups (for example, acetyl or benzoylgroups), carbalkoxy groups (for example, carbomethoxy or carbethoxygroups), ether groups (for example, alkoxy groups), and also keto,hydroxyl or amino groups. 60

Especially valuable results are obtained with S-alkylandS-aralkyl-isothiuronium salts which contain at least four carbon atomsin the isothiuronium cation.

Suitable S-isothiuronium derivatives are, for example,- as follows:S-methyl-, S-ethyl-, S-isopropyl-, S-tertiarybutyl-, S-tertiary-amyl-,S-cyclohexylor S-lauryl-isothiuronium chloride or bromide,S-carbomethoxymethylisothiuronium chloride,S-carbethoxymethyl-isothiuronium chloride, S-acetonyl-isothiuroniumchloride and above all S-benzyl-isothiuronium chloride.

These isothiurea derivatives to be used in the present 2,865,910 9Patented Dec. 23, 1958 process can be made by methods in themselvesknown, for example, by reacting thiourea in aqueous or alcoholicsolution or suspension with an organic compound containing mobilehalogen atoms, especially an organic compound containing a single mobilechlorine atom. There are advantageously used organic compounds which arefree from substituents imparting solubility in water. Thus, thiourea maybe reacted, for example, with methyl, ethyl, isopropyl, tertiary amyl,cyclohexyl or lauryl chloride or with chloracetone, bromacetone,chloracetic acid methyl or ethyl ester or above all with benzyl chloridein water, in acetone or in alcohol at the boiling temperature of thereaction mixture. The isothiuronium halides so obtained may, forexample, be separated by filtration or the reaction mixture may be usedas such in the process of the invention. Instead of the aforesaidisothiuronium halides there may be used other isothiuronium salts, forexample, isothiuronium acetate or isothiuronium sulfonate such as areobtainable, for example, from para-toluene sulfonic acid alkyl esters byreaction with thiourea.

The reaction of the aforesaid thiourea derivatives with the aforesaiddyestuffs is advantageously carried out in an aqueous medium at a raisedtemperature or at ordinary temperature, if desired, in the presence of asuitable addition.

It is desirable to use a reaction medium which is neither too stronglyalkaline nor too strongly acid, as under such conditions theisothiuronium salts may decompose at least partially. Accordingly, it isof advantage to use a practically neutral or Weakly acid medium. Thedyestufis are advantageously used in the form of their soluble salts,preferably their alkali metal salts. Thus, for example, an aqueoussolution or partial suspension of one or more dyestuff alkali metalsalts may be mixed with a solution or suspension of an isothiuroniumsalt in the cold or if desired at a raised temperature, and theprecipitated dyestuff isothiuronium salt, which is generally practicallyinsoluble in water, is separated, for example, by filtration. Bythoroughly washing it with water, the product can be obtainedpractically free from inorganic salts.

The products of the present process are new. are valuable isothiuroniumsalts which are very They sparingly soluble to insoluble in water, andof which the anion is that of an acid chromium monoazo-dyestuff.Especially valuable are those isothiuronium salts of chromiferousmonoazo-dyestuffs, of which the isothiuronium cation contains bound tothe sulfur atom through an alkylene or alkylidene group an aliphatic oraromatic radical containing at least three carbon atoms and free fromgroups imparting solubility in water, for example, an S-alkylorS-aralkyl-isothiuronium salt of a monoazo dyestuff chromium complexcontaining a sulfonic acid group.

These new products are valuable dyestufis and generally possess a goodsolubility in various organic solvents such as are customarily used forthe production of lacquers and spinning masses, especiallyacetylcellulose spinning masses. They are also suitable as pigments oras transparent dyestuffs for dyeing natural or artificial waxes orresins, for example, polyvinyl chloride, cellulose esters or Celluloid.They are generally-distinguished by a good fastness to light and goodfastness to migration and sublimation.

The following examples illustrate the invention, the parts andpercentages being by weight:

Example I 30 parts of the chromiferous dyestutl" from diazotized 1amino-2-hydroxynaphthalene-4-sulfonic acid and1-hydroxynaphthalene-8-sulfonic acid, which contains one atom ofchromium per molecule of dyestuii, are dissolved in 1000 parts of water.Into the resulting solution there is run slowly at room temperature asolution of 40 parts of S-benzyl-isothiuronium chloride in 200 parts ofwater. The isothiuronium salt of the dyestuii precipitates completely,and is filtered olf and washed with water. The dry dyestufi is a darkblue powder which dissolves easi.y in alcohol with a blue coloration. Asolution of the dyestuff in nitrocellulose lacquer when applied to asuitable substratum yields coatings of good fastness to light.

Similar isothiuronium salts are obtained from the lzl-chromium complexesof the ortho:ortho'-dihydroxymonoazo-dyestufis obtained from thediam-components and coupling components in columns a and b of thefollowing table by reacting them in a manner analogous to that describedabove with the isothiuronium compounds given in column 0. In column dare given the tints of coatings produced with nitrocellulose lacquersExample 3 parts of the chromiferous azo dyestuff from diazotized4-nitro-2-amino-l-hydroxybenzene-G-sulfonic acid andl-phenyl-3-methyl-5-pyrazolone, which contains one atom of chromium permolecule of dycstuff, are dissolved in 1500 parts of water, and thesolution is mixed at room temperature with a solution of 30 parts ofS-lauryl-isothiuronium chloride in 100 parts of water. The precipitatedS-lauryl-isothiuronium-dyestufi sulfonate containing the dyestuff. isfiltered ofi and dried. It is a brown powder which Diazo componentsCoupling components I b e 4 NH; HO 5 0 blue. 1 -0H HBr.HzN-C=NH -C Ha801E NH, HO son: 2 0H HC1.HaN-G= Do.

S-CnHn NH! H0 S01};

3 OH HC1.H;N--0=NH Do.

S-CHrCO-O-CzH:

NH| H0 801B 4. -0H HC1.H:N(3=NH crime: no.

S-G CH:

CHaCH:

80: OH Hfi-.-C-CHI HO-C N 5 HOgS NH; \N/ HCl.HzN-C=NH orange.

-C|Hn dissolves easily in alcohol and acetone, and dyes celluloseExample 2 acetate artificial silk spinning masses orange tints.

' parts of the chromiferous dyestutr from diazotized 6 nitro 1 amino 2hydroxynaphthalene 4 sulfonic acid and Z-hydroxynaphthalene, whichcontains about /2 atomic proportion of chromium per molecular proportionof dyestuif, are dissolved at C. in 1000 parts of water. After coolingthe solution to 35 C., there is added in the course of one hour asolution of 36 parts of S-amyl-isothiuronium chloride in 100 parts ofwater. The precipitated dyestufi salt is filtered ofi, Washed free fromsalts with water and dried. It is a black powder 75 What is claimed is:p

1. An isothiuronium salt of an acid chromiferous monoazo dyestuff whichis a complex chromium compound of anortho:ortho'-dihydroxy-monoazo-dyestufi, containing a sulfonic acidgroup and one atom of chromium bound in complex union per molecule of amonoazo-dyestuii selected from the'group consisting of benzene-azo-pyrazolone dyestufis and naphthalene-azanaphthol dyestuffs. 2. An S-alkylisothiuronium salt of anacid chromitchromium compound of anortho:ortho'-dihydroxymono- 15 azo-dyestufi containing a sulfonic acidgroup.

5. The S-benzyl isothiuronium salt of the complex chromium compoundcontaining one atom of chromium bound in complex union with one moleculeof the monoazo-dyestufi which in the free acid state corresponds to theformula OH HO SOgH 6. The S-amyl isothiuronium salt of the complexchromium compound containing one atom of chromium bound in complex unionwith o azo-dyestuif which in the free the formula HO 5 H I /CN H 033-N=NC i 10 CH:

7. The S-benzyl isothiuronium salt of chromium compound containing oneatom bound in complex union with s responds to me molecule of themonoacid state corresponds to the complex of chromium ubstantially twomolecules oazo-dyestuff which in its free acid state corthe formulaReferences Cited in the file of this patent UNITED STATES PATENTSGraenacher et a1 Clarke et al.

Nov. 24, 1954 Oct. 23, 1956

1. AN ISOTHIURONIUM SALT OF AN ACID CHROMIFEROUS MONOAZO DYESTUFF WHICHIS A COMPLEX CHROMIUM COMPOUND OF ANORTHO:ORTHO''-DIHYDROXY-MONOAZO-DYESTUFF, CONTAINING A SULFONIC ACIDGROUP AND ONE ATOM OF CHROMIUM BOUND IN COMPLEX UNION PER MOLECULE OF AMONOAZO-DYESTUFF SELECTED FROM THE GROUP CONSISTING OFBENZENE-AZO-PYRAZOLONE DYSTUFFS AND NAPHTHALENE-AZONAPHTHOL DYESTUFFS.